The present invention relates generally to bale wagons and, more particularly, to a pickup mechanism for engaging bales lying on the ground and elevating them onto a bale receiving table mounted on the bale wagon.
Generally, bale wagons are provided with a pickup mechanism, sometimes referred to as a loader, for engaging bales lying on the ground and elevating them onto the bale wagon to form a stack. Typically, the pickup will include an elevator, usually in the form of a chain conveyor having bale engaging members mounted thereon, to convey bales from the ground onto the bale wagon. The elevator is normally driven by a drive mechanism having a drive shaft delivering rotational power from a prime mover and a power transfer member mounted on the shaft to transfer rotational power from the shaft to the elevator.
When the bale wagon is moving along the ground faster than the driven speed of the elevator, any bale being picked up from the ground cannot be elevated at a sufficient rate to prevent the bale from being broken. A known solution for this problem is to provide an overrunning clutch between the elevator and the drive shaft to permit the movement of the bale into the pickup mechanism to accelerate the elevator, thereby elevating the bale from the group at a rate corresponding to the ground speed of the bale wagon. Once the bale has been elevated off the ground, the elevator can decelerate to the speed at which it is driven by the drive shaft. However, overrunning clutches are expensive, and it is desirable to provide a less expensive device to permit the elevator to overrun the drive shaft and, thereby, maintain integrity of the shape of the packaged bale.